Engine compartment cooling apparatus

Abstract

When the temperatures of engine coolant and outside-air are above respective predetermined values immediately after the engine has stopped, a fan to cool the engine is operated for a predetermined time interval, thereby preventing engine compartment from being heated excessively.

What is claimed is: 
     
       1. Apparatus for cooling an engine compartment of a vehicle, comprising: (a) first detecting means for sensing the cessation of engine operation to produce a stop signal;   (b) second detecting means for sensing the temperature of engine coolant to produce a coolant signal when the temperature of the coolant is above a predetermined value;   (c) third detecting means for sensing the temperature of outside air to produce an outside-air signal when the temperature of the outside air is above a predetermined value;   (d) means for driving a fan for cooling the engine; and   (e) means responsive to the stop signal, coolant signal and outside-air signal for actuating said driving means for a predetermined time interval.   
     
     
       2. Apparatus as set forth in claim 1, wherein said first detecting means senses the absense of ignition voltage. 
     
     
       3. Apparatus as set forth in claim 1, wherein said actuating means includes an AND gate responsive to the presence of the stop signal, coolant signal and outside-air signal to produce a triggering signal, a monostable multivibrator responsive to said triggering signal for producing a second triggering signal for a predetermined time interval, switching means responsive to the second triggering signal for connecting electric drive power to said driving means. 
     
     
       4. Apparatus as set forth in claim 1, wherein said actuating means includes an AND gate resposive to the outside-air signal and the stop signal to produce a triggering signal, a monostable multivibrator resposive to the triggering signal to produce a second triggering signal for said predetermined time interval, a thermal-responsive switch responsive to the temperature of the coolant when the temperature of the coolant is above the predetermined value to produce a switching signal, and means responsive to the triggering signal and the switching signal for closing a circuit through which electric drive power is supplied to said driving means. 
     
     
       5. Apparatus as set forth in claim 1, wherein said first detecting means senses the absence of voltage at a neutral point of the alternator for charging the vehicle battery. 
     
     
       6. Apparatus as set forth in claim 3 or 4, further including means disposed between said AND gate and said monostable multivibrator for eliminating possible electric noises.